Tokyo prosecutors have charged camera-maker Olympus and three of its former executives in connection with a $US1.7 billion accounting cover-up.
The company's former chairman, executive vice-president and auditor are among those charged with falsifying securities reports, the BBC reports.
Olympus has admitted to hiding the losses for over 20 years in one of Japan's biggest corporate scandals.
The cover-up came to light in October last year after former chief executive, Michael Woodford, claimed he was fired for questioning accounting practices at the firm.
Mr Woodford said he had raised specific concerns about Olympus' payment of $US687 million to financial advisers during the acquisition of UK medical equipment company Gyrus.
Though Olympus initially denied his claims, the firm later admitted that it had been hiding losses for almost two decades.